There are several key parameters that must be considered when developing a good denitrifying granular sludge. First, the proper seed sludge must be chosen (VSS/SS at 0.65-0.75, SRT over 25 days) to accelerate the granulation process. Secondly, any floating sludge should be stirred, and the sludge loading rate should be within the range of 0.05-0.15 gNO3-N gVSS鈭? d鈭? until fine granules emerge. Additionally, spontaneous gas agitation or interval air-blowing should be used to effectively eliminate channelling; Finally, the sludge loading rate should be less than 0.25 gNO3-N gVSS鈭? d鈭? until dense, mature granular sludge appears. This study could support and promote the full-scale application of denitrifying granular sludge.